/* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.acegisecurity.util;

import org.springframework.util.Assert;
import org.springframework.util.StringUtils;

import java.util.HashMap;
import java.util.Map;
import java.util.ArrayList;
import java.util.List;


/**
 * Provides several <code>String</code> manipulation methods.
 *
 * @author Ben Alex
 * @version $Id: StringSplitUtils.java,v 1.1 2009/06/22 11:43:32 cvs Exp $
 */
public final class StringSplitUtils {
    //~ Static fields/initializers =====================================================================================
    private static final String[] EMPTY_STRING_ARRAY = new String[0];

    //~ Constructors ===================================================================================================

    private StringSplitUtils() {
    }

    //~ Methods ========================================================================================================

    /**
     * Splits a <code>String</code> at the first instance of the delimiter.<p>Does not include the delimiter in
     * the response.</p>
     *
     * @param toSplit   the string to split
     * @param delimiter to split the string up with
     * @return a two element array with index 0 being before the delimiter, and index 1 being after the delimiter
     *         (neither element includes the delimiter)
     * @throws IllegalArgumentException if an argument was invalid
     */
    public static String[] split(String toSplit, String delimiter) {
        Assert.hasLength(toSplit, "Cannot split a null or empty string");
        Assert.hasLength(delimiter, "Cannot use a null or empty delimiter to split a string");

        if (delimiter.length() != 1) {
            throw new IllegalArgumentException("Delimiter can only be one character in length");
        }

        int offset = toSplit.indexOf(delimiter);

        if (offset < 0) {
            return null;
        }

        String beforeDelimiter = toSplit.substring(0, offset);
        String afterDelimiter = toSplit.substring(offset + 1);

        return new String[]{beforeDelimiter, afterDelimiter};
    }

    /**
     * Takes an array of <code>String</code>s, and for each element removes any instances of
     * <code>removeCharacter</code>, and splits the element based on the <code>delimiter</code>. A <code>Map</code> is
     * then generated, with the left of the delimiter providing the key, and the right of the delimiter providing the
     * value.<p>Will trim both the key and value before adding to the <code>Map</code>.</p>
     *
     * @param array            the array to process
     * @param delimiter        to split each element using (typically the equals symbol)
     * @param removeCharacters one or more characters to remove from each element prior to attempting the split
     *                         operation (typically the quotation mark symbol) or <code>null</code> if no removal should occur
     * @return a <code>Map</code> representing the array contents, or <code>null</code> if the array to process was
     *         null or empty
     */
    public static Map splitEachArrayElementAndCreateMap(String[] array, String delimiter, String removeCharacters) {
        if ((array == null) || (array.length == 0)) {
            return null;
        }

        Map map = new HashMap();

        for (int i = 0; i < array.length; i++) {
            String postRemove;

            if (removeCharacters == null) {
                postRemove = array[i];
            } else {
                postRemove = StringUtils.replace(array[i], removeCharacters, "");
            }

            String[] splitThisArrayElement = split(postRemove, delimiter);

            if (splitThisArrayElement == null) {
                continue;
            }

            map.put(splitThisArrayElement[0].trim(), splitThisArrayElement[1].trim());
        }

        return map;
    }

    public static String substringBeforeLast(String str, String separator) {
        if (str == null || separator == null || str.length() == 0 || separator.length() == 0) {
            return str;
        }
        int pos = str.lastIndexOf(separator);
        if (pos == -1) {
            return str;
        }
        return str.substring(0, pos);
    }

    public static String substringAfterLast(String str, String separator) {
        if (str == null || str.length() == 0) {
            return str;
        }
        if (separator == null || separator.length() == 0) {
            return "";
        }
        int pos = str.lastIndexOf(separator);
        if (pos == -1 || pos == (str.length() - separator.length())) {
            return "";
        }
        return str.substring(pos + separator.length());
    }

    /**
     * Splits a given string on the given separator character, skips the contents of quoted substrings
     * when looking for separators.
     * Introduced for use in DigestProcessingFilter (see SEC-506).
     * <p/>
     * This was copied and modified from commons-lang StringUtils
     */
    public static String[] splitIgnoringQuotes(String str, char separatorChar) {
        if (str == null) {
            return null;
        }

        int len = str.length();

        if (len == 0) {
            return EMPTY_STRING_ARRAY;
        }

        List list = new ArrayList();
        int i = 0;
        int start = 0;
        boolean match = false;

        while (i < len) {
            if (str.charAt(i) == '"') {
                i++;
                while (i < len) {
                    if (str.charAt(i) == '"') {
                        i++;
                        break;
                    }
                    i++;
                }
                match = true;
                continue;
            }
            if (str.charAt(i) == separatorChar) {
                if (match) {
                    list.add(str.substring(start, i));
                    match = false;
                }
                start = ++i;
                continue;
            }
            match = true;
            i++;
        }
        if (match) {
            list.add(str.substring(start, i));
        }

        return (String[]) list.toArray(new String[list.size()]);
    }

}
